Oscillating mass for a watch



FIG. 1 is a front view of my new, original and ornamental design for an oscillating mass for a watch;

FIG. 2 is a rear view thereof;

FIG. 3 is a right side view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a top view thereof;

FIG. 6 is a bottom view thereof; and,

FIG. 7 is a front perspective view thereof. 

The ornamental design for an oscillating mass for a watch, as shown and described. 